Train control system



Feb; 2; 1932. R. c. BURNS ET AL 1,843,539

TRAIN coNTRbL SYSTEM Filed March '7, 1929 3 Sheets-Sheet 1 IN VEN TOR:

BY W ATTORNEYS.

Feb. 2, 1932. R. c. BURNS ET'AL 1,843,539

TRAIN CONTROL SYSTEM Filed March '7. 1929 5 Sheets-Sheet 2 W1 TNESSES IN VCE N TOR Feb. 2, 1932. R. c. BURNS ET AL 1,343,539

TRAIN CONTROL SYSTEM Filed March 7, 1929 5 Sheets-Sheet 5 FIC'ZEZWITNESSES INVENTOR:

Baberi LLBzzrJzs Lesier 6k Pia/22.22,

WMWM K BY I A TTORNEYS.

Patented Feb. 2, 1 932 aem oFFicE ROBERT C. BURNS, OF BELLWOOD, ANDLESTER G. BLANK, OF HOLLIDAYSBURG, PENNSYLVANIA TRAIN CONTROL SYSTEMApplication filed March 7,-

Our invention relates to traincontrol systems in which instrumentalitieson a train respond to currents in wayside circuits to cause cab signalindications and, under certain cir- 5 cumstances, to causean automatictrain stop operation. More particularly the invention relates to acombined brake application and cut-off valve which serves as the directmeans of controlling the functions involved in automatically applyingthe train brakes.

The object of the invention is to provide, in apparatus of the abovetype, means for preventing the engineman from defeating an automatictrain stop operation. To accom- 15. plish this object the equipmentsupplied on the train includes means for automatically applying thebrakes a fter'a certain cab signal indication is given; means'forcutting oii" an air supply to cause the operation of electrical 0devices now in general use; andm'eans for 7 cutting off all supply ofcompressed air to the brake valve, thus preventing the engineman fromreleasing the brakes and'so defeating an automatic train stopapplicationby any movement of the brake valve or double heading cook.The above-mentioned means are incorporated in a combined brakeapplication and cut-off valve,'which forms the subject of the presentinvention and which can be installed in connection with the presentstandard brake equipment and with any of the train stop systems now inuse without necessitating the use of additional apparatus such asreservoirs, equalizing pistons and the like.

Other objects and advantages of our invention will be apparent from thedetailed description which follows and which has reference to theaccompanying drawings, in which there is shown one embodiment of theinvention. Of the drawings: I

Fig. I is a diagrammatic view showing the combined brake application andcut-oil valve, in connection with a part of the appa- Qratus' on thetrain comprising the train c0ntrol system;

Fig. II is a diagrammatic View showing the remainder of the apparatus ofthe train controlsystem, including such parts of stand- 1929. Serial No.345,132.

ard air brake equipment as it is necessary to describe for the properunderstanding of our invention;

V Fig. III is an enlarged view of the combined application and cut-offvalve of Fig. I,' showing thes'ame in its normal position; and,

' 'Fig. IV isa similar viewexeept that the valve' 5, similarlydesignated. In Figs. 1,

II and III the apparatus is shown in its normal running position, inwhich case there is no interference with the normal function ofeachpart.

In Fig. I there is-diagrammatically illustrated a part ofthe electricalapparatus comprising the receiving equipment on the train which isresponsive to the wayside transmitting equipment. The receivingequipment is of a type now in general use and servesto provide acontinuous cab signal indication to the engineman informing him oftraffic conditions in advance. This equipment also interlocks with thepneumatic equipment to initiate a brake application should the enginemanfail to acknowledge a change to a more restrictive signal indi-. cation.For this purpose, a pneumatic circuit controller 6 and the combinedmagnet and application control valve 3 are employed. There is alsoprovided an acknowledgment switch 7 by which the engineman may forestallan automatic train stop, and a reset-switch 8, preferably locatedbeneath the cab so as to require the engineman to descend to the groundto release the brakes. The electrical equipment is shown in the 100normal running position with a clear cab signal.

The engineman may, in this system, apply the brakes through either theautomatic brake valve 1 or the independent brake valve 4 at any time andto any degree permissible in usual air brake practice. Application ofthe train brakes is effected by reducing the air pressure in the brakepipe 9, accomplished, as usual, through the medium of the automaticbrake valve 1 by moving the handle to the service or emergency position.Main reservoir pressure supplies air via pipe 13 and port 16 to achamber G in the application and cut-ofi' valve 2, thence through pipe20 and a feed valve 22 to the chamber of the rotary valve 23 of theautomatic brake valve '1. The air passes through a port 24 in the bottomrotary valve seat and a port 18 to a double heading cock 26 and thenceto the brake pipe 9, Manual service or emergency application isaccomplished in the usualmanner by reducing the brake pipe ressureraduall for service a alication' and rapidly for emergency application.

When a train stop operation occurs, on account of the enginemans failingto acknowledge a change to a more restrictive indication, the magnetvalve 3 becomes de-energized and vents the timing reservoir 31 toatmosphere at 48 and through a restricted port 32 to the warning Whistle33 which sounds continuously for several seconds. The port 32 is soproportioned that at the end of approximately six seconds, the piston 47and upper timing valve 34 will move downward by means of the pressureexerted by the spring 35. This movement of the timing valve connectschamber 29 to atmosphere, and hence likewise connects a chamber of thebrake application valve 2 to atmosphere through pipe 10.

Normally, the main reservoir pressure on both sides of the brakeapplication valve piston 36 is in equilibrium. When, however,

pipe 10 is vented to atmosphere by the train stop apparatus, thepressure in chamber K is reduced below that in chamber H causing thepiston 36 to move downward until the cut-01f valve 37 strikes its seat,thus preventing any flow of air from the main reservoir through pipe 13to pipe 59 and thence to pipe 20, and thus preventing any further supplyof air to the automatic brake valve 1. At the same time cavity E of theslide valve 38 connects port 39 to port 15, the latter port beingconnected to the usual holding pipe 40 of the automatic brake valve 1,thus establishing a direct vent of pipe 10 and chamber K as long as thebrake valve is left in running position. The movement of the slide valve38 also by'means'of cavity C connects port 11 to atmosphere through port46,. thus establishing through pipe 41 a vent of the brake pipe 9,should the engineman attempt to de-.

valve 59, allowing brake pipe air to flow to the atmosphere at 60. Port61 being restricted, the pressure in the equalizing reservoir 28 and thechamber above the equalizing piston 27 falls gradually. The movement ofthe slide valve 38 also connects pipe 42 through port 25, cavity A, andport 45 to atmosphere, and thus brake pipe pressure is removed from thepneumatic circuit controller 6 and atmospheric pressure substitutedtherefor. This operates the circuit controller 6 in suchmanner as toopen the circuit to the acknowledging switch 7 so that the magnet valve30 can.

only be re-energized by operating the reset switch'8. Accordingly, thebrake may not be released by acknowledgment following an automatic trainstop application.

It will thus be seen that when the combined application and cut-ofl,valve is moved to the position shown in Fig. IV the'following operationstake place:

1. There is established, a direct vent of chamber K to the, atmospherewhich condi-. tion continues until the automatic brake valveis movedfrom running position to lap position.

2. There is established a vent of brake pipe 9 to the atmosphere whichcondition continues regardless of the position of the double headingcock 26.

'3. The equalizing reservoir 28 is connected to the reduction limitingreservoir 43.

4. All supply of air from the main reser-. voirto the automaticbrakevalve 1 is cut-off.

5. A direct ventof the pneumatic circuit controller 6 is establisheduntil the brake application valve 2 is returned to normal position. V

To reset the train stop apparatus, the automatic brake valve 1 mustfirst be placed in lap position to close the atmosphere vent of pipe 40through port 44 in the brake valve.

Then when the train stops, the engineman descends to the groundandoperates the reset switch 8. This i e-energizes the magnet valve 30 andcloses the remaining vent of pipe 10 to-atmosphere. Upon moving thebrake valve, 1 from running position to lap position and closing pipe40, pressure in the chamber K will become equal to that in chamber H and.TELllOW:tl16 spring 49 to force the piston 36 andslide valve 38tonormal position thus.

venting the reduction limiting reservoir air 43 through cavity C andsupplying air to pipe 42 through, port 25 and cavity A and closing thecircuit to the acknowledging switch 7. I

In Fig. II of the drawings there is shown the usual compressor governor50 in the pipe 51 leading from the compressor. The pipe 13 leading fromthe main reservoir at 52 has a branch connection 53 through a reducingvalve 54 to the independent brake valve 4. An application cylinder pipe55 leads from the independent brake valve 4 to the automatic brakevalve 1. An additional pipe 56 connects the distributing valve 5 throughthe independent brake valve 4 with the holding pipe 40 of the automaticbrake valve 1. Connections to the driver brake cylinders and tendercylinders are shown at 57 and 58, respectively. The apparatus of Fig. IIcomprises well known equipment which is merely illustrated to show thecomplete pneumatic system with which the brake application valve 2operates.

It will be apparent from the description that the novel construction andarrangement of the brake application valve, together with its variousconnections to other apparatus of the train control system produces aneffective safeguard preventing the engineman, once a train stopoperation has been initiated, from defeating the operation by anymovement other than the operation of the reset switch which firstnecessitates a complete train stop.

The combined brake applicationand cutoff valve 2 may be installed inconnection with standard brake equipment now in use, and, though simplein construction, it serves as the direct means of controlling all thepneumatic functions involved in automatic brake application andnecessitates no additional reservoirs or other apparatus. It may beconveniently located contiguous to the automatic brake valve, so thatthe pipe connec tions to the brake valvemay be of minimum length orentirely eliminated.

While we have described the invention with some particularity, it is tobe understood that the form and type of the various valves and otherapparatus shown may be varied without departing from the spirit of ourinvention, which contemplates any train control system within thedefinition of the claims here appended.

Having thus described our invention, we claim:

1. In a train control system, a brake valve, a brake pipe, a doubleheading cock interposed between said brake pipe and brake valve, andelectro-pneumatic means responsive to wayside currents for automaticallyoperating the equalizing piston of said brake valve to effect anautomatic train stop, said means including a brake application valveassociated with said brake valve and having means for cutting meansincluding a combined application and cut-oil valve having connectionswith said brake valve and having means for venting said brake pipethrough said double heading cock if an attempt is made to defeat a trainstop operation by closing said double heading COC 3. In a train controlsystem, a brake Valve and electro-pneumatic means responsive to waysidesignals for automatically operating the equalizing piston of said brakevalve to effect an automatic train stop, said means including anelectrical device by which a signal preliminary to an automatic trainstop operation may be acknowledged and the stop prevented, and a brakeapplication valve associated with said brake valve and having means forcutting ofi' all supply of air to said brake valve upon an automatictrain stop operation and having means for simultaneously opening acircuit to said acknowledging device whereby the automatic train stopoperation, once initiated, cannot be prevented by the engineman.

4. In a train control system, a main reservoir; a brake valve havingpneumatic connections with said reservoir and with a train brake pipe,and having an equalizing piston for reducing pressure in said brakepipe; electro-pneumatic means, responsive to wayside currents to effectan automatic train stop, including a magnet valve, an application valveapart from said brake valve, and a pneumatic circuit controllerconnected to said main reservoir through said application valve, saidapplication valve having means for cutting off all supply of air fromthe main reservoir to said brake valve, having means for causing theoperation of the brake valve to effect a train stop, and having meansfor venting the circuit controller.

5. In a train control system, a brake valve, a brake pipe, a doubleheading cock interposed between said brake pipe and brake valve,electro-pneumatic means responsive to wayside currents for automaticallyoperating said brake valve to effect an automatic train stop, said meansincluding an application valve associated with said brake valve andhaving means for cutting 0E all supply of air to said brake valve uponan automatic train stop, and a connection from said double heading cockto said application valve whereby uponan attempt to defeat a train stopoperation by closing said double heading Cock, the brake pipe Will bevented through said application valve- I In testimony whereof, We havehereunto signed our names at Altoona, Pennsylvania, this 2d day ofMarch, 1929* ROBERT C. BURNS.

LESTER G.'PLANI.

